(a) Field of the Invention
The present invention is related to a light emitting diode construction, and more particularly, to one that improves light use efficiency, increases light emitting angle, and a backlight module applying the light emitting diode to upgrade its light emitting efficiency.
(b) Description of the Prior Art
An Surface Mounted Device (SMD) light emitting diode 1 of the prior art as illustrated in FIGS. 1 and 2 of the accompanying drawings includes a casing 11 disposed with two first sides and two second sides 111 and 112 opposite to each other; a compartment 113 defined by both sides 111 and both sides 112; a light emitting chip 12 being received at the bottom of the compartment 113 wherein two lead-frames 13 and 14 are also accommodated to respectively define two soldering portions 131 and 141; the light emitting chip 12 being respectively electrically connected to both soldering portions 131 and 141 by means of leading wires 15; and a packaging colloid 16.
However, the packaging colloid 16 in the compartment 113 has a flat surface and a total reflection is produced when the reflectivity of the packaging colloid 16 is 1.41 and the angle of incidence of the light emitted from the light emitting chip 12 entering into the packaging colloid 16 is greater than 45° indicating the light is prevented from leaving the packaging colloid 16. When the light is totally reflected by the packaging colloid 16 or is reflected from the bottom of the packaging colloid 16 to both sides 111 and 112 of the casing 11, the light is confined in the packaging colloid 16 with certain portion of the light will produce further total reflection to prevent light from effectively leaving the packaging colloid thus to compromise use efficiency of light.